On Mon, Apr 15, 2024 at 09:12:11AM +0800, Hongbo Li wrote:
>
>
> On 2024/4/14 5:57, Kent Overstreet wrote:
> > For those interested, this is a good tour of the facilities for rolling
> > out new on disk format features.
> >
> > -- >8 --
> >
> > This adds a small (64 bit) per-device bitmap that tracks ranges that
> > have btree nodes, for accelerating btree node scan if it is ever needed.
> >
> > - New helpers, bch2_dev_btree_bitmap_marked() and
> > bch2_dev_bitmap_mark(), for checking and updating the bitmap
> >
> > - Interior btree update path updates the bitmaps when required
> >
> > - The check_allocations pass has a new fsck_err check,
> > btree_bitmap_not_marked
> >
> > - New on disk format version, mi_btree_mitmap, which indicates the new
> > bitmap is present
> >
> > - Upgrade table lists the required recovery pass and expected fsck error
> >
> > - Btree node scan uses the bitmap to skip ranges if we're on the new
> > version
> >
> > Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> > ---
> > fs/bcachefs/bcachefs_format.h | 7 ++--
> > fs/bcachefs/btree_gc.c | 13 +++++++
> > fs/bcachefs/btree_node_scan.c | 9 +++--
> > fs/bcachefs/btree_update_interior.c | 24 +++++++++++++
> > fs/bcachefs/sb-downgrade.c | 5 ++-
> > fs/bcachefs/sb-errors_types.h | 3 +-
> > fs/bcachefs/sb-members.c | 53 +++++++++++++++++++++++++++++
> > fs/bcachefs/sb-members.h | 21 ++++++++++++
> > fs/bcachefs/sb-members_types.h | 2 ++
> > 9 files changed, 131 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
> > index 9480f1b44f07..085987435a5e 100644
> > --- a/fs/bcachefs/bcachefs_format.h
> > +++ b/fs/bcachefs/bcachefs_format.h
> > @@ -578,7 +578,8 @@ struct bch_member {
> > __le64 nbuckets; /* device size */
> > __le16 first_bucket; /* index of first bucket used */
> > __le16 bucket_size; /* sectors */
> > - __le32 pad;
> > + __u8 btree_bitmap_shift;
> > + __u8 pad[3];
> > __le64 last_mount; /* time_t */
> > __le64 flags;
> > @@ -587,6 +588,7 @@ struct bch_member {
> > __le64 errors_at_reset[BCH_MEMBER_ERROR_NR];
> > __le64 errors_reset_time;
> > __le64 seq;
> > + __le64 btree_allocated_bitmap;
> > };
> > #define BCH_MEMBER_V1_BYTES 56
> > @@ -876,7 +878,8 @@ struct bch_sb_field_downgrade {
> > x(rebalance_work, BCH_VERSION(1, 3)) \
> > x(member_seq, BCH_VERSION(1, 4)) \
> > x(subvolume_fs_parent, BCH_VERSION(1, 5)) \
> > - x(btree_subvolume_children, BCH_VERSION(1, 6))
> > + x(btree_subvolume_children, BCH_VERSION(1, 6)) \
> > + x(mi_btree_bitmap, BCH_VERSION(1, 7))
> > enum bcachefs_metadata_version {
> > bcachefs_metadata_version_min = 9,
> > diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
> > index 10c41cf89212..a77c723a9cef 100644
> > --- a/fs/bcachefs/btree_gc.c
> > +++ b/fs/bcachefs/btree_gc.c
> > @@ -822,6 +822,7 @@ static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
> > struct bch_fs *c = trans->c;
> > struct bkey deleted = KEY(0, 0, 0);
> > struct bkey_s_c old = (struct bkey_s_c) { &deleted, NULL };
> > + struct printbuf buf = PRINTBUF;
> > int ret = 0;
> > deleted.p = k->k->p;
> > @@ -842,11 +843,23 @@ static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
> > if (ret)
> > goto err;
> > + if (mustfix_fsck_err_on(level && !bch2_dev_btree_bitmap_marked(c, *k),
> > + c, btree_bitmap_not_marked,
> > + "btree ptr not marked in member info btree allocated bitmap\n %s",
> > + (bch2_bkey_val_to_text(&buf, c, *k),
> > + buf.buf))) {
> > + mutex_lock(&c->sb_lock);
> > + bch2_dev_btree_bitmap_mark(c, *k);
> > + bch2_write_super(c);
> > + mutex_unlock(&c->sb_lock);
> > + }
> > +
> > ret = commit_do(trans, NULL, NULL, 0,
> > bch2_key_trigger(trans, btree_id, level, old,
> > unsafe_bkey_s_c_to_s(*k), BTREE_TRIGGER_gc));
> > fsck_err:
> > err:
> > + printbuf_exit(&buf);
> > bch_err_fn(c, ret);
> > return ret;
> > }
> > diff --git a/fs/bcachefs/btree_node_scan.c b/fs/bcachefs/btree_node_scan.c
> > index 20f2b37c4474..866bd278439f 100644
> > --- a/fs/bcachefs/btree_node_scan.c
> > +++ b/fs/bcachefs/btree_node_scan.c
> > @@ -205,8 +205,13 @@ static int read_btree_nodes_worker(void *p)
> > last_print = jiffies;
> > }
> > - try_read_btree_node(w->f, ca, bio, buf,
> > - bucket * ca->mi.bucket_size + bucket_offset);
> > + u64 sector = bucket * ca->mi.bucket_size + bucket_offset;
> > +
> > + if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_mi_btree_bitmap &&
> > + !bch2_dev_btree_bitmap_marked_sectors(ca, sector, btree_sectors(c)))
> > + continue;
> > +
> > + try_read_btree_node(w->f, ca, bio, buf, sector);
> > }
> > err:
> > bio_put(bio);
> > diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
> > index 593241b15aa8..12ce6287416f 100644
> > --- a/fs/bcachefs/btree_update_interior.c
> > +++ b/fs/bcachefs/btree_update_interior.c
> > @@ -21,6 +21,7 @@
> > #include "keylist.h"
> > #include "recovery_passes.h"
> > #include "replicas.h"
> > +#include "sb-members.h"
> > #include "super-io.h"
> > #include "trace.h"
> > @@ -644,6 +645,26 @@ static int btree_update_nodes_written_trans(struct btree_trans *trans,
> > return 0;
> > }
> > +static bool btree_update_new_nodes_marked_sb(struct btree_update *as)
> > +{
> > + for_each_keylist_key(&as->new_keys, k)
> > + if (!bch2_dev_btree_bitmap_marked(as->c, bkey_i_to_s_c(k)))
> > + return false;
> > + return true;
> > +}
> > +
> > +static void btree_update_new_nodes_mark_sb(struct btree_update *as)
> > +{
> > + struct bch_fs *c = as->c;
> > +
> > + mutex_lock(&c->sb_lock);
> > + for_each_keylist_key(&as->new_keys, k)
> > + bch2_dev_btree_bitmap_mark(c, bkey_i_to_s_c(k));
> > +
> > + bch2_write_super(c);
> > + mutex_unlock(&c->sb_lock);
> > +}
> > +
> > static void btree_update_nodes_written(struct btree_update *as)
> > {
> > struct bch_fs *c = as->c;
> > @@ -664,6 +685,9 @@ static void btree_update_nodes_written(struct btree_update *as)
> > if (ret)
> > goto err;
> > + if (!btree_update_new_nodes_marked_sb(as))
> > + btree_update_new_nodes_mark_sb(as);
> > +
> > /*
> > * Wait for any in flight writes to finish before we free the old nodes
> > * on disk:
> > diff --git a/fs/bcachefs/sb-downgrade.c b/fs/bcachefs/sb-downgrade.c
> > index 56ac8f35cdc3..90b06f8aa1df 100644
> > --- a/fs/bcachefs/sb-downgrade.c
> > +++ b/fs/bcachefs/sb-downgrade.c
> > @@ -51,7 +51,10 @@
> > BCH_FSCK_ERR_subvol_fs_path_parent_wrong) \
> > x(btree_subvolume_children, \
> > BIT_ULL(BCH_RECOVERY_PASS_check_subvols), \
> > - BCH_FSCK_ERR_subvol_children_not_set)
> > + BCH_FSCK_ERR_subvol_children_not_set) \
> > + x(mi_btree_bitmap, \
> > + BIT_ULL(BCH_RECOVERY_PASS_check_allocations), \
> > + BCH_FSCK_ERR_btree_bitmap_not_marked)
> > #define DOWNGRADE_TABLE()
> > diff --git a/fs/bcachefs/sb-errors_types.h b/fs/bcachefs/sb-errors_types.h
> > index d7d609131030..5b600c6d7aca 100644
> > --- a/fs/bcachefs/sb-errors_types.h
> > +++ b/fs/bcachefs/sb-errors_types.h
> > @@ -270,7 +270,8 @@
> > x(btree_ptr_v2_min_key_bad, 262) \
> > x(btree_root_unreadable_and_scan_found_nothing, 263) \
> > x(snapshot_node_missing, 264) \
> > - x(dup_backpointer_to_bad_csum_extent, 265)
> > + x(dup_backpointer_to_bad_csum_extent, 265) \
> > + x(btree_bitmap_not_marked, 266)
> > enum bch_sb_error_id {
> > #define x(t, n) BCH_FSCK_ERR_##t = n,
> > diff --git a/fs/bcachefs/sb-members.c b/fs/bcachefs/sb-members.c
> > index 9b7a2f300182..d5937aba0910 100644
> > --- a/fs/bcachefs/sb-members.c
> > +++ b/fs/bcachefs/sb-members.c
> > @@ -1,6 +1,7 @@
> > // SPDX-License-Identifier: GPL-2.0
> > #include "bcachefs.h"
> > +#include "btree_cache.h"
> > #include "disk_groups.h"
> > #include "opts.h"
> > #include "replicas.h"
> > @@ -378,3 +379,55 @@ void bch2_dev_errors_reset(struct bch_dev *ca)
> > bch2_write_super(c);
> > mutex_unlock(&c->sb_lock);
> > }
> > +
> > +/*
> > + * Per member "range has btree nodes" bitmap:
> > + *
> > + * This is so that if we ever have to run the btree node scan to repair we don't
> > + * have to scan full devices:
> > + */
> > +
> > +bool bch2_dev_btree_bitmap_marked(struct bch_fs *c, struct bkey_s_c k)
> > +{
> > + bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
> > + if (!bch2_dev_btree_bitmap_marked_sectors(bch2_dev_bkey_exists(c, ptr->dev),
> > + ptr->offset, btree_sectors(c)))
> > + return false;
> > + return true;
> > +}
> > +
> > +static void __bch2_dev_btree_bitmap_mark(struct bch_sb_field_members_v2 *mi, unsigned dev,
> > + u64 start, unsigned sectors)
> > +{
> > + struct bch_member *m = __bch2_members_v2_get_mut(mi, dev);
> > + u64 bitmap = le64_to_cpu(m->btree_allocated_bitmap);
> > +
> > + u64 end = start + sectors;
> > +
> > + int resize = ilog2(roundup_pow_of_two(end)) - (m->btree_bitmap_shift + 6);
> > + if (resize > 0) {
> > + u64 new_bitmap = 0;
> > +
> > + for (unsigned i = 0; i < 64; i++)
> > + if (bitmap & BIT_ULL(i))
> > + new_bitmap |= BIT_ULL(i >> resize);
> > + bitmap = new_bitmap;
> > + m->btree_bitmap_shift += resize;
> > + }
> > +
> > + for (unsigned bit = sectors >> m->btree_bitmap_shift;
> > + bit << m->btree_bitmap_shift < end;
> > + bit++)
> > + bitmap |= BIT_ULL(bit);
> > +
> > + m->btree_allocated_bitmap = cpu_to_le64(bitmap);
> > +}
> > +
> > +void bch2_dev_btree_bitmap_mark(struct bch_fs *c, struct bkey_s_c k)
> > +{
> > + lockdep_assert_held(&c->sb_lock);
> > +
> > + struct bch_sb_field_members_v2 *mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
> > + bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
> > + __bch2_dev_btree_bitmap_mark(mi, ptr->dev, ptr->offset, btree_sectors(c));
> > +}
> > diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h
> > index bc3bcfef7b3a..8bbad30a4370 100644
> > --- a/fs/bcachefs/sb-members.h
> > +++ b/fs/bcachefs/sb-members.h
> > @@ -3,6 +3,7 @@
> > #define _BCACHEFS_SB_MEMBERS_H
> > #include "darray.h"
> > +#include "bkey_types.h"
> > extern char * const bch2_member_error_strs[];
> > @@ -234,6 +235,8 @@ static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
> > : 1,
> > .freespace_initialized = BCH_MEMBER_FREESPACE_INITIALIZED(mi),
> > .valid = bch2_member_alive(mi),
> > + .btree_bitmap_shift = mi->btree_bitmap_shift,
> > + .btree_allocated_bitmap = le64_to_cpu(mi->btree_allocated_bitmap),
> > };
> > }
> > @@ -242,4 +245,22 @@ void bch2_sb_members_from_cpu(struct bch_fs *);
> > void bch2_dev_io_errors_to_text(struct printbuf *, struct bch_dev *);
> > void bch2_dev_errors_reset(struct bch_dev *);
> > +static inline bool bch2_dev_btree_bitmap_marked_sectors(struct bch_dev *ca, u64 start, unsigned sectors)
> > +{
> > + u64 end = start + sectors;
> > +
> > + if (end > 64 << ca->mi.btree_bitmap_shift)
> > + return false;
> > +
> > + for (unsigned bit = sectors >> ca->mi.btree_bitmap_shift;
> > + bit << ca->mi.btree_bitmap_shift < end;
> > + bit++)
> > + if (!(ca->mi.btree_allocated_bitmap & BIT_ULL(bit)))
> Should it be transferred by le64_to_cpu?
no, ca->mi is bch_member_cpu, a different type that has everything in
native byte order
